Robert t



(No Model.)

B. T. ABELL.

STEAM ENGINE.

No. 403,714. Patented May 21 1889.

w INVENTOR.

WITNESSES 7h)? ATTORZVEY NITED STATES ATENT OFFICE.

ROBERT T. ABELL, OF CLEVELAND, OlllO, ASSIGNOR OF TlVO-THIRDS TO lVESLEYROYCE AND J OIIN H. FRANCIS, BOTH OF SAME PLACE.

STEAM-ENGINE.

SPECIFICATION forming part of Letters Patent No. 403,714, dated May 21,1889.

Application filed November 26, 1888. Serial No. 291,834. (No model.)

To all whom it may concern:

Be it known that I, ROBERT T. ABELL, of Cleveland, in the county ofCuyahoga and State of Ohio, have invented certain new and isometric viewin detail corresponding in scale with Fig. 1.

The steanrcylinder consists of outer and inner concentric rims,respectively, A and A, and head A integral with these rims, and aremovable head, 13, each head having a central hub projecting outward,and in the bore of these hubs are j ournaled, respectively, rockshafts CC. These shafts, at the inner ends thereof, either abut or come in closeproximity to each other. On the inner ends of these shafts are mounted,respectively, disks 0 C, each disk, on the inner face thereof, havinglatorally-projecting lugs c c, the lugs of the two disks interlocking,but having play enough between them circumferentially to accommodate thereverse oscillations of the two shafts. Each lug c is recessed on theface thereof in a radial direction to receive a radial arm, 0, thearrangement being such that the two sets of arms all operate in the sameor central plane of the cylinder. These arms extend through and operatein slots (4 of the inner rim, A. The outer ends of these arms areslightly conical and fit in corresponding seats in the respectivepistons D D, the outer ends of each arm being screw-threaded andprovided with nut c to hold the piston firmly to its seat on the arm,the pistons on the outer periphery thereof having recesses that admitthe nuts below the surface of the pistons. It will be observed that twopistons, D, are attached to the same set of arms and are locateddiametrically opposite each other, while the pistons D are mounted onthe other set of arms and are located in the same relative position toeach other, and consequently the two pistons of a set balance each otherperfectly.

The pistons of small engines may be solid; but for larger engines theyshould be cored or chambered to lighten them, the ends of the pistonsbeing all that necessarily lit the cylinder, and any suitable packingmaybe used to secure tight joints with the cylinder at the ends of thepistons.

Shafts 0, outside their journal-bearings, are provided with rock-arms E,and these arms are connected by pitmen cwith cranks F, the latter beingmounted on the respective ends of shaft F and extending in oppositedirections from the shaft. This shaft is provided with a fly-wheel andwith a band-wheel, or whatever may be necessary to transmit the power ofthe engine. The cylinder is provided with the same number of cylindricalsteam-chambers a as there are pistons-in the present instance four thesesteam-chambers being located, respectively, opposite the points of themain cylinder where opposing piston ends nearest approach each other, asshown, with ports a? connecting each steam-chamber with the maincylinder, each steam-chamber, of course, having induction and ed uctionpipes a and a". Each steam-chamber is provided with an oscillatingvalve, G, of ordinary construction, one such valve being shown at 'thetop in Fig. 1. As heretofore, the one trunnion of each oscillating valveextends through a suitable stulling-box in the removable head of thesteam-chamber, such trunnion having attached an arm,g, and each armgbeing connected by a link, g, with a disk, ll, the latter being mountedloose on the shaft 0, that projects from this side of the engine. Disk11 is connected by eccentric-rods h with eccentric h, the latter beingmounted on shaft F. The valves are given the necessary lead to cushionthe opposing ends of the pistons as they come in close proximity to eachother, and the valves have suitable lap, more or less, according as itis desired to use steam more or less cxpansively. lVhile two oppositevalves-for instance, the valves at top and bottomare admitting steam thevalves located on the side are exhausting steam, and vice versa, all ofwhich will be readily understood by persons skilled in the art. As theaxes of the steam-chambers are parallel with the axis of the maincylinder, these chambers need not be separated but a short distance fromthe bore of the main cylinder, by reason of which the ports, although ofample width and extending the full length of the cylinder, may be soshort in a radial direction that it requires but little steam to fillthe port, and consequently the waste steam from such cause may bereduced to a minimum. The perfect balance attained with this engineadapts it to high speed without tendency to shake or vibrate. The enginemay be arranged to have the valves on the quarters, instead of at top,bottom, and sides, if so preferred.

WVith this variety of engine four pistons are preferable to two, for thereason that two pistons would not balance each other, except by means ofthe connection with the crankshaft. The engine may be constructed withsix, eight, or more pistons, if for any reason it were foundadvantageous to do so.

lVhat I claim is 1. The combination, with a steam-cylinder.

heads secured against the outer edges of the rims, of segmental pistonsarranged in series, the pistons of one series operating between thepistons of the other series, each series of pistons being mounted on arock-shaft independent of the rock-shaft of the other series, but havinga common axial line, substantially as set forth.

3. The combination, with a steam-cylinder composed of two concentriccircular rimsand heads secured against the outer edges of the rims, ofsegmental pistons located between the rims and arranged in series, thepistons of one series operating between the pistons of the other series,rock-shafts, arms passing through the inner rim and connecting thepistons and rock-shafts, and a rock-arm mounted on each rock-shaft, thesaid rock-arms being connected by pitmen with a crank-shaft,substantially as set forth.

4. The combination, with a steam-cylinder and segmentaloperating-pistons arranged in two series and operating in said cylinder,of

ROBERT T. ABELL.

Witnesses: V

CHAS. H. DORER, ALBERT E. LYNCH.

